| Plasma-cable-type seven-wire MIG welding is an efficient welding method that combines plasma arc,MIG arc and cable-type welding.Plasma arc is a kind of compression arc,the rigidity of the arc is large,can form deep melting in the welding process,MIG arc melting wire,can ensure the filling of the melting pool.Using cable wire welding,arc is a unique beam arc,temperature concentration,multi-pole coupling,high efficiency and energy saving.Because of its wide application range,good welding quality and high welding efficiency,it is of great significance to the study of its welding process.This article selects the Q235 composite plate welding as the research object,with cable type welding wire as fill welding wire,numerical analysis model is established using GAMBIT software,the plasma-cable-type seven wire MIG compound welding process,to simulate the flow field and temperature of molten pool in the occasions for molten pool fluid behavior rule.According to building the model of plasma-compound MIG welding pool fluid numerical simulation analysis of the process,found that as the whole of the welding process,the molten pool of the weld width broaden,deepened and depth of molten weld pool size is more big,the molten pool temperature is higher and higher,plate temperature interval range is more and more wide,molten pool fluid motion is more and more intense,molten pool oscillation is obvious.Compare with ordinary plasma welding or ordinary MIG welding,plasma-MIG composite welding has a smaller scope of action than MIG welding,larger than plasma welding,smaller heat input to the welding seam,smaller range of heat affected area,slow cooling,enough time for the bubble to escape,improve the welding efficiency and ensure the quality of welding.Then simulates the different welding parameters on plasma-compound MIG welding molten pool fluid flow behavior in the process of impact,the conclusion is as follows: the welding speeds of the three groups were 0.5m/min,0.6m/min and 0.7m/min,respectively with the rise of the welding speed,small pool of molten pool,the weld residual high increases after the first decreases,and use rope type than using common welding wire,welding wire welding molten pool of the weld width is small,melting depth is deeper,more high is higher,molten pool in the speed of fluid motion.Three groups of MIG currents were selected,respectively 280 A,320A and 340 A,with the increase of MIG current,the melting width and residual height of the melting pool increase.Compared with the ordinary welding wire,the welding using cable wire has smaller melting width,deeper melting depth and higher residual height.Three groups of plasma currents were selected as 240 A,260A and 280 A,respectively.with the increase of plasma current,the molten width of the molten pool increase and the residual height decreases.Compared with ordinary welding wire,the molten pool has smaller molten width,higher residual height and similar molten depth,and the velocity of fluid movement in the molten pool increases.Through comparison,it can be concluded that compared with ordinary wire welding,cable wire welding has deeper depth and more concentrated heat,which can effectively reduce the volume of heat affected zone and is more suitable for highefficiency welding.Finally,in order to verify the accuracy of simulation results,some plasma-MIG composite welding tests were carried out,and the accuracy of simulation results was verified by comparing the change rules of molten pool and the sectional morphology of molten pool. |
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